Connect EA to PSN to share games?

I have a PS4 and I play Fifa21 there. I now want to play Fifa21 on the PC. You can connect the EA account to PSN. Can you then play Fifa21 on your PC using Origin? Or what is the point of combining both accounts?

So my goal: I want to play Fifa21 on the PC but don't want to buy a new one because I bought it on the PS4 anyway. Is that possible?

As soon as EA says that they willingly forego more money, your wish will come true.
In short, they will never do that.

Thanks. Right. But one more question: do you know what the linking of accounts will bring?

That can be different from game to game or platform to platform, but mostly you can transfer saved games or something similar.